The present invention relates to an electrical connector for flexible printed board called FPC (Flexible Printed Circuit).
There has been provided a technique for directly connecting a circuit on a printed circuit board with a contact of a connector. Conventionally, the connector of this type includes a synthetic-resin housing having an opening adapted to open upward, a plurality of fork-shaped contacts arranged to face into the opening, and a synthetic-resin cover which is pivotally movable to open/close the opening of the housing. The fork-shaped contact has a fixing piece and a resilient piece vertically opposed each other.
The connector of this type provides a wide insertion space for FPC as the flexible printed board, for example, when the cover is opened for insertion or removal of the FPC. This contributes an unconfined state of the FPC such that the FPC may be inserted in place without using an inserting force or pulled out without using a pulling force. Thus, the FPC is prevented from being damaged during insertion or removal thereof.
As the connector allowing the insertion or removal of the FPC under unconfined conditions, there have been provided a variety of connectors of a lower contact point type. In the connector of lower contact point, a contact point is provided only at the resilient piece on the lower side. One edge of the cover in closed position is clamped between the FPC resting on the resilient piece and the fixing piece on the upper side so that the FPC is pressed against the resilient piece by means of the clamped edge of the cover.
On the other hand, there is a demand for a connector of an upper contact point type which features an increased freedom with respect to the connection with the FPC and which provides the contact point only at the resilient piece disposed on the upper side.
The following publication has been published by the Japanese Patent Office pertaining a type of connector adapted for connection of stripped conductor ends of a multiple conductor flat cable via the upper and lower contact points.
Country: Japan
Publication Number: 1(1989)-315976 (unexamined)
Published Date: Dec. 20, 1989.
The connector of the above official gazette has a lever arm extended from a distal end of the resilient piece to place above one edge of the cover in closed position. When the cover is opened, the edge of the cover pushes up the lever arm to expand a gap between the two contact points, thereby facilitating the insertion or removal of FPC. Additionally, the lever arm applies a resilient reaction force to the one edge of the cover in open position, thereby maintaining the cover in open position.
In the connector of the above official gazette, however, an upward displacement of the resilient piece is not restricted. Hence, the resilient piece is subjected to plastic deformation when pushed up by some external force. As a result, the resilient piece is incapable of providing a sufficient contact pressure on the FPC.
In view of the foregoing, the present invention has been accomplished and has an object to provide an upper contact point type connector for flexible printed board which ensures a sufficient contact pressure by preventing an excessive deformation of the contact.
For achieving the above object, an electrical connector for flexible printed board according to a preferred embodiment of the invention comprises: a synthetic-resin housing having an opening; a plurality of fork-shaped contacts being arranged to face into the opening, each of the contact having a resilient piece and a fixing piece in opposed relation; an insertion space for flexible printed board defined between the resilient piece and the fixing piece; and a synthetic-resin cover being rotatable around a predetermined pivotal axis to open or close the opening. The plural fork-shaped contacts include a fork-shaped contact including a first and a second branches branched from a free end of the resilient piece. The second branch adjoins the insertion space. The second branch includes a contact point pressed into contact with a flexible printed board inserted in the insertion space. One edge of the cover includes a regulating portion interposed between the first and the second branches for bidirectionally restricting a range of displacement of the free end of the resilient piece.
According to the embodiment hereof, the range of displacement of the free end of the resilient piece can be bidirectionally restricted by the regulating portion disposed at the one edge of the cover sandwiched between the first and the second branches. Therefore, an excessive deformation of the contact may be prevented. As a result, the so-called connector of upper contact point type can ensure a sufficient contact pressure on the flexible printed board at all times. Further, damage on the contact or the flexible printed board is prevented, the damage resulting from the excessive deformation of the contact.
It is particularly preferred that the regulating portion includes a cam surface for pushing the first branch into displacement thereby expanding the insertion space in conjunction with the opening of the cover. In this case, a wide insertion space for flexible printed board is provided when the cover is opened.
It is further preferred that the cam surface moves away from the first branch in conjunction with the closing of the cover. This eliminates the displacement of the first branch caused by the cam surface when the cover is closed. Therefore, the resilience of the resilient piece may be utilized to provide a sufficient contact pressure on the flexible printed board.